In the lead-up to the Democratic presidential debate Friday night, I found myself reflecting frequently on last month's Bernie Sanders/Elizabeth Warren post-debate exchange, in which each accused the other of having called them a liar on national TV. Or, more precisely, I found myself ruminating on fellow candidate Tom Steyer's role in that pivotal moment.

In the lead-up to the Democratic presidential debate Friday night, I found myself reflecting frequently on last month's Bernie Sanders/Elizabeth Warren post-debate exchange, in which each accused the other of having called them a liar on national TV. Or, more precisely, I found myself ruminating on fellow candidate Tom Steyer's role in that pivotal moment.